Astronomical extreme events or phenomena include black holes as well as nebulae systems that resemble the Milky Way. Meteorological extreme events or phenomena include tornadoes and tropical cyclones. The new high ene...Astronomical extreme events or phenomena include black holes as well as nebulae systems that resemble the Milky Way. Meteorological extreme events or phenomena include tornadoes and tropical cyclones. The new high energy state of matter expanding outwards by spin jets from the two poles of an astronomical black hole, the new high energy state of matter in a funnel-shaped vortex showed a meteorological tornado expanding downwards from a rotated disk of cumulonimbus clouds, the new high energy state of matter in a tropical cyclone and the new high energy state of a nebulae system converging celestial materials are phenomena across disciplines and multiple time-space scales that have not yet been physically explained. In this paper, the theory of orthogonal collision in the rotational contraction continuum is used to unify the understanding of diverse extreme events or phenomena through a single dynamical mechanism, offering insights into natural processes across disciplines. In the field of astronomy, the orthogonal collision of two-beam rotating and contracting particles or stars associated with centripetal forces forms a new high-energy state of matter at the collision point and the new high-energy particles have expanding forces outward to both sides of the collision plane. In the field of meteorology, the orthogonal collision of multiple horizontally rotating and contracting airflows associated with centripetal forces forms a new high energy state of matter at the collision point as well as an updraft force and a downdraft force vertically. The updraft force and downdraft force formed by the collision of anomalous wet airflows in the lower atmosphere can well indicate tornado, thunderstorm and extreme precipitation. The orthogonal collision theory can be applied to explain new states of matter in disciplines from the astronomical scale to the meteorological scale and the Planck scale.展开更多
Dear Readers:Antarctica,with its unparalleled atmospheric transparency,extended polar nights,and unique geographical position,has become a premier site for modern astronomical observation.Two decades ago,the Chinese A...Dear Readers:Antarctica,with its unparalleled atmospheric transparency,extended polar nights,and unique geographical position,has become a premier site for modern astronomical observation.Two decades ago,the Chinese Antarctic Research Expedition(CHINARE)team reached Dome A,the highest point of the Antarctic ice sheet,marking the beginning of a new era for astro-nomical research from the Antarctic plateau.展开更多
The rapid development of optical neural networks(ONNs)has led to the introduction of new research avenues for computing power enhancement.Because of the characteristics of optical signals,which include low power consu...The rapid development of optical neural networks(ONNs)has led to the introduction of new research avenues for computing power enhancement.Because of the characteristics of optical signals,which include low power consumption,low latency,high parallelism,and large bandwidths,optical computing based on neural network architectures is showing promise for processing of spatial signals,temporal signals,and on-chip information.At present,there is a lack of a unified ONN computing architecture,and because of the limitations of the physical characteristics of these networks,different application scenarios have led to proposals of different requirements for the structural design,device selection,integration method,and signal processing method of the network.In this paper,we systematically elaborate on the practical value of ONNs,analyze their computational fundamentals in depth,discuss the challenges faced in computational and astrophotonics applications in detail,and simultaneously emphasize the important position and broad prospects of optical computing in the future information society.展开更多
In the first part of this paper,we describe briefly the mid and long-term plan of Chinese space astronomy,its preliminary study program,the current status of satellite missions undertaken, and the current status of as...In the first part of this paper,we describe briefly the mid and long-term plan of Chinese space astronomy,its preliminary study program,the current status of satellite missions undertaken, and the current status of astronomy experiments in China's manned space flight program.In the second part,the recent research progress made in the fields of solar physics is summarized briefly, including solar vector magnetic field,solar flares,CME and filaments,solar radio and nonthermal processes,EUV waves,MHD waves and coronal waves,solar model and helioseismology,solar wind and behavior of solar cycle.展开更多
More and more proposals, or potential projects have been proposed in recent two years. We try to briefly outline these new proposals, although most of them are in fact only in their conception studies. The progress of...More and more proposals, or potential projects have been proposed in recent two years. We try to briefly outline these new proposals, although most of them are in fact only in their conception studies. The progress of previously mentioned projects, like Space Solar Telescope (SST), the Hard X-ray Modulation Telescope (HXMT), as well as newly initiated LUnar Resource Explorer (LUREX), will be introduced elsewhere.展开更多
In this biographical account, I recall my scientific journey that began in 1961 when I joined as a Physics Trainee in the BARC Training School and after one year course was admitted in TIFR as a Research Associate. Du...In this biographical account, I recall my scientific journey that began in 1961 when I joined as a Physics Trainee in the BARC Training School and after one year course was admitted in TIFR as a Research Associate. During 1962–1967, I worked on determination of the He^3 /He^4 ratio in cosmic rays using a gas Cerenkov counter and also used a scintillation + solid Cerenkov detector to measure flux of protons and helium nuclei in primary cosmic rays. I also developed a large area scintillation-Cerenkov detector with a spark chamber between them for measuring charge composition of primary cosmic rays. I joined the X-ray astronomy programme in 1967 initiated by Prof. B. V. Sreekantan and played a leading role in developing a balloon borne hard X-ray instrument for studying time variability and energy spectra of cosmic X-ray sources. We carried out a series of balloon experiments and studied temporal intensity variation and energy spectra of X-ray objects like Sco X-1, Cyg X-1, etc. Results on rapid intensity changes and spectra appeared in a series of publications based on which I obtained a Ph.D. degree in 1972. Immediately afterwards, I joined Prof. Gordon Garmire at Caltech as a Research Fellow (a post-doctoral position) to work with him on the low energy component of HEAO A-2 experiment. The instrument was developed and successfully realised. Working on this satellite experiment was a thrilling experience which exposed me to the technical complexities of space instruments. The HEAO-1 satellite was launched in 1978. During 1978–1979, Guenter Riegler and I, working at JPL, reported detection of intense soft X-rays from several classes of extragalactic and Galactic objects like new BL Lacs, a new AM Her binary, coronal X-rays from active stars, etc. After returning to TIFR, I developed a rocket experiment with K. P. Singh to map the spatial and spectral distribution of the Soft Diffuse X-ray Background. At the same time, I also designed 15 cm deep Xenon filled Proportional Counters (XPCs) of ~ 2500 cm^2 area for balloon experiments which were done during 1983–1990 and produced new results on several X-ray binaries. During this period I also developed a proportional counter (PC) based satellite instrument and submitted a proposal jointly with the astronomy group at the Indian Space Research Organization (ISRO) for an Indian X-ray Astronomy Experiment (IXAE). After success of the Polar Satellite Launch Vehicle (PSLV), the IXAE instrument was included on the top deck of the IRS-P3 satellite that was launched in March 1996. Despite the severe limitation of a polar orbit, the IXAE observed a good number of X-ray binaries and produced interesting results, with the most notable being quasi-regular bursts from a new transient, GRS 1915+105, which turned out to be an enigmatic black hole source. Following success of the IXAE, a proposal for an ambitious multiwavelength astronomy satellite, named ASTROSAT, with broad spectral coverage in the optical, NUV, FUV, soft X-ray and hard X-ray by a suite of instruments, was submitted to ISRO and finally approved by the Govt. of India in 2004. Over the next 10 years, the development and fabrication of the five ASTROSAT instruments were accomplished and a PSLV launch on Sept. 28, 2015 placed ASTROSAT in a 650 km circular orbit with 6 degree inclination. The ASTROSAT instruments have been performing well for ~4 years and have observed more than 500 cosmic sources. Results from ASTROSAT have appeared in a large number of journal publications. Successful realization and performance of ASTROSAT marks culmination of my research career. I formally retired as a Senior Professor from TIFR on 2006 April 30 on attaining the age of superannuation. However by agreement with TIFR, ISRO designated me ‘ISRO Chair Professor’, which was later renamed as ISRO Satish Dhawan Professor, and asked me to continue to lead ASTROSAT as PI. At the end of my tenure as ISRO Professor on 2011 April 30, I relinquished the PI position. I am at present affiliated with the MU-DAE Centre of Excellence for Basic Sciences, Mumbai University Campus at Mumbai as an Emeritus Professor.展开更多
For the past two years, some real progress has been made in Chinese Space Astronomy, though we have not launched any missions exclusively belonging to the scope of Astronomy. In order to program the next five years...For the past two years, some real progress has been made in Chinese Space Astronomy, though we have not launched any missions exclusively belonging to the scope of Astronomy. In order to program the next five years' national plan (2006-2010), the Chinese Space Agency organized a series of authorized evaluations for the future missions. Among more than ten astronomical mission proposals, several were selected to give the green light to continue for their Phase A studies. We try to briefly outline these proposals.展开更多
In 2008 to 2010,the main activities in Chinese space astronomy were focused on:fulfilling the long-term plan of Chinese space astronomy;initiating the long-term plan of Chinese space astronomy;undertaking some astrono...In 2008 to 2010,the main activities in Chinese space astronomy were focused on:fulfilling the long-term plan of Chinese space astronomy;initiating the long-term plan of Chinese space astronomy;undertaking some astronomical missions set by CNSA in "Development Program of Space Science for 2006-2010".This paper summarizes in brief all these activities.展开更多
In 2006 to 2008,the main activities in Chinese space astronomy focus on:(1) undertaking some missions set by CNSA,like HXMT,SMESE,WSO/UV,SST,KUAFU,and so on;(2) drawing up a long-term plan of Chinese space astronomy.T...In 2006 to 2008,the main activities in Chinese space astronomy focus on:(1) undertaking some missions set by CNSA,like HXMT,SMESE,WSO/UV,SST,KUAFU,and so on;(2) drawing up a long-term plan of Chinese space astronomy.This paper summarizes in brief all these activities.展开更多
Silicon microstrip detectors are widely used in experiments for space astronomy.Before the detector is assembled,extensive characterization of the silicon microstrip sensors is indispensable and challenging.This work ...Silicon microstrip detectors are widely used in experiments for space astronomy.Before the detector is assembled,extensive characterization of the silicon microstrip sensors is indispensable and challenging.This work electrically evaluates a series of sensor parameters,including the depletion voltage,bias resistance,metal strip resistance,total leakage current,strip leakage current,coupling capacitance,and interstrip capacitance.Two methods are used to accurately measure the strip leakage current,and the test results match each other well.In measuring the coupling capacitance,we extract the correct value based on a SPICE model and two-port network analysis.In addition,the expression of the measured bias resistance is deduced based on the SPICE model.展开更多
I returned to China from the United Kingdom in 1953, then worked in Purple Mountain Observatory. It was the early days of new China. The elder generation of astronomers was undertaking an effort of ＂repairing broken ...I returned to China from the United Kingdom in 1953, then worked in Purple Mountain Observatory. It was the early days of new China. The elder generation of astronomers was undertaking an effort of ＂repairing broken and filling defect＂ during those post-war years, and started planning and lay- ing the foundation of modern astronomy. Under their leadership, I started a journey of astronomy whose main task was construction. The journey has been full of twists and turns. As a result of the ＂Great Leap Forward＂ in 1958 and the 1966 launch of the decade-long ＂Cultural Revolution＂ period, the situation of construction in astronomy was similar to that in other sciences, suffering bad effects. Not until the ＂Reform and Opening up＂ period after those events was construction able to continue, and various disciplines and international connections began to open. A ＂passage＂ had gradually developed. In this new circumstance, I kept pursuing the pioneers to explore a forward direction. Looking back today, this journey has been three periods of a four generation relay. This article is divided into three sections that describe my research work in these times that I recall： （1） Looking back at the beginning of the return and tracing the footprints of the founders. （2） Recalling my radio astronomy tour. （3） Retrospection and expectation of LAMOST.展开更多
The Educational Adaptive-optics Solar Telescope(EAST)at the Shanghai Astronomy Museum has been running routine astronomical observations since 2021.It is a 65-cm-aperture Gregorian solar telescope for scientific educa...The Educational Adaptive-optics Solar Telescope(EAST)at the Shanghai Astronomy Museum has been running routine astronomical observations since 2021.It is a 65-cm-aperture Gregorian solar telescope for scientific education,outreach,and research.The telescope system is designed in an“open”format so that the solar tower architecture can be integrated with it,and visitors can watch the observations live from inside the tower.Equipped with adaptive optics,a high-resolution imaging system,and an integral field unit spectro-imaging system,this telescope can obtain high-resolution solar images in the TiO and Hαbands,and perform spectral image reconstruction using 400 optical fibers at selected wavelengths.It can be used not only in public education and scientific outreach but also in solar physics research.展开更多
Space research is usually costly, and this restricts participation of developing countries. With traditional techniques one must construct high resolution instrument,more and more complicated and expensive, to obtain ...Space research is usually costly, and this restricts participation of developing countries. With traditional techniques one must construct high resolution instrument,more and more complicated and expensive, to obtain high resolution results from space observations. It is a difficult task to make observations with both high sensitivity and high resolution. Applying advanced inversion technique, one can subtract more information from old data in public domain,and, furthermore, conduct high sensitive and high-resolution experiments with low-cost low-resolution instruments. So developing and applying data analysis technique is of great importance for developing countries to do basic space science.In this paper we summarize efforts of Chinese scientists in recent years along this direction on imaging in space high energy astronomy.展开更多
Atmospheric transmission from Dome A, Antarctica, presents new possibilities in the field of terahertz astronomy, where space telescopes have been the only observational tools until now. Using atmospheric transmission...Atmospheric transmission from Dome A, Antarctica, presents new possibilities in the field of terahertz astronomy, where space telescopes have been the only observational tools until now. Using atmospheric transmission measurements from Dome A with a Fourier transform spectrometer, transmission spectra and long-term stabilities have been analyzed at 1.461 THz, 3.393 THz, 5.786 THz and 7.1 THz, which show that important atmospheric windows for terahertz astronomy open for a reasonable length of time in the winter season. With large aperture terahertz telescopes and interferometers at Dome A, high angular resolution terahertz observations are foreseen of atomic fine-structure lines from ionized gas and a water ice feature from protoplanetary disks.展开更多
The French astronomer Charles Messier (1730- 1817) compiled a catalogue [1] of astronomical objects which reached109 innumber after additions by later astronomers were added. The catalogue contains galaxies, emission ...The French astronomer Charles Messier (1730- 1817) compiled a catalogue [1] of astronomical objects which reached109 innumber after additions by later astronomers were added. The catalogue contains galaxies, emission nebulae, a supernova remnant, a double star, globular clusters, open clusters, an asterism, a star cloud, and planetary nebulae. While the objective of Messier in compiling the catalogue was to guide comet hunters not to be confused by his objects which he thought looked like comets [2], the Messier Catalogue as it later became known became a standard guide to astronomers for a study of the sky’s “greatest hits” or the best samples of objects which can be observed and studied. This paper explores the value of the Messier Catalogue in the teaching of Astronomy and Earth Science. The range of objects is wide and contains some of the best examples of their type. The teaching method I propose is the actual observations of the objects through a telescope, with the corresponding explanation. Some principles which will be covered through this process are stellar evolution from the birth and death of stars, galaxy types, formation of galaxies, galactic interactions, life in the Universe, cosmology, and our place in the Universe.展开更多
To automate the process of planning and curating multi-target observation sessions, pysky application builds on the astroplan Python package to identify visible objects during an observation window and produce relevan...To automate the process of planning and curating multi-target observation sessions, pysky application builds on the astroplan Python package to identify visible objects during an observation window and produce relevant information about those objects in visual and graphical form. The package calculates object visibility based on a provided time window and observing location as well as maximum airmass and limiting magnitude requested by the user. The pysky application images of the target objects with identifying and astrometric data to provide context for the images. In addition, pysky creates polar plots of each object’s horizontal coordinates, and the images and plots are designed to be shown side-by-side. The package also generates an HTML table of the selected target objects with their related data to relay the entire target list as one. The pysky application draws on a variety of Python packages to collect and process data from databases such as JPL Horizons and SIMBAD. Results for a test event were verified by hand using database web interfaces. The pysky application provides a platform for further integration of automated observation planning with websites and apps to enhance multi-target observation sessions.展开更多
This chapter reports the recent progress on the space astronomy missions of China,including the following missions:currently operating in orbit,e.g.,DAMPE,Insight-HXMT,GECAM,Polar Light,GRID and Lobster-eye X-ray Sate...This chapter reports the recent progress on the space astronomy missions of China,including the following missions:currently operating in orbit,e.g.,DAMPE,Insight-HXMT,GECAM,Polar Light,GRID and Lobster-eye X-ray Satellite;approved and under development for launch in the next a couple of years,e.g.,SVOM and EP;planned experiments to be onboard China’s Space Station in the next several years,e.g.,CSST,HERD,POLAR-2,DIXE and Ly RIC;candidate missions that have passed the first round of review of Strategy Priority Program on space science(Ⅲ)of the Chinese Academy of Sciences,e.g.,eXTP,DAMPE-2,Earth 2.0,DSL and CHES.展开更多
文摘Astronomical extreme events or phenomena include black holes as well as nebulae systems that resemble the Milky Way. Meteorological extreme events or phenomena include tornadoes and tropical cyclones. The new high energy state of matter expanding outwards by spin jets from the two poles of an astronomical black hole, the new high energy state of matter in a funnel-shaped vortex showed a meteorological tornado expanding downwards from a rotated disk of cumulonimbus clouds, the new high energy state of matter in a tropical cyclone and the new high energy state of a nebulae system converging celestial materials are phenomena across disciplines and multiple time-space scales that have not yet been physically explained. In this paper, the theory of orthogonal collision in the rotational contraction continuum is used to unify the understanding of diverse extreme events or phenomena through a single dynamical mechanism, offering insights into natural processes across disciplines. In the field of astronomy, the orthogonal collision of two-beam rotating and contracting particles or stars associated with centripetal forces forms a new high-energy state of matter at the collision point and the new high-energy particles have expanding forces outward to both sides of the collision plane. In the field of meteorology, the orthogonal collision of multiple horizontally rotating and contracting airflows associated with centripetal forces forms a new high energy state of matter at the collision point as well as an updraft force and a downdraft force vertically. The updraft force and downdraft force formed by the collision of anomalous wet airflows in the lower atmosphere can well indicate tornado, thunderstorm and extreme precipitation. The orthogonal collision theory can be applied to explain new states of matter in disciplines from the astronomical scale to the meteorological scale and the Planck scale.
文摘Dear Readers:Antarctica,with its unparalleled atmospheric transparency,extended polar nights,and unique geographical position,has become a premier site for modern astronomical observation.Two decades ago,the Chinese Antarctic Research Expedition(CHINARE)team reached Dome A,the highest point of the Antarctic ice sheet,marking the beginning of a new era for astro-nomical research from the Antarctic plateau.
基金supported by the National Key R&D Program of China(2021YFC2202100)the National Natural Science Foundation of China(12473090).
文摘The rapid development of optical neural networks(ONNs)has led to the introduction of new research avenues for computing power enhancement.Because of the characteristics of optical signals,which include low power consumption,low latency,high parallelism,and large bandwidths,optical computing based on neural network architectures is showing promise for processing of spatial signals,temporal signals,and on-chip information.At present,there is a lack of a unified ONN computing architecture,and because of the limitations of the physical characteristics of these networks,different application scenarios have led to proposals of different requirements for the structural design,device selection,integration method,and signal processing method of the network.In this paper,we systematically elaborate on the practical value of ONNs,analyze their computational fundamentals in depth,discuss the challenges faced in computational and astrophotonics applications in detail,and simultaneously emphasize the important position and broad prospects of optical computing in the future information society.
文摘In the first part of this paper,we describe briefly the mid and long-term plan of Chinese space astronomy,its preliminary study program,the current status of satellite missions undertaken, and the current status of astronomy experiments in China's manned space flight program.In the second part,the recent research progress made in the fields of solar physics is summarized briefly, including solar vector magnetic field,solar flares,CME and filaments,solar radio and nonthermal processes,EUV waves,MHD waves and coronal waves,solar model and helioseismology,solar wind and behavior of solar cycle.
文摘More and more proposals, or potential projects have been proposed in recent two years. We try to briefly outline these new proposals, although most of them are in fact only in their conception studies. The progress of previously mentioned projects, like Space Solar Telescope (SST), the Hard X-ray Modulation Telescope (HXMT), as well as newly initiated LUnar Resource Explorer (LUREX), will be introduced elsewhere.
文摘In this biographical account, I recall my scientific journey that began in 1961 when I joined as a Physics Trainee in the BARC Training School and after one year course was admitted in TIFR as a Research Associate. During 1962–1967, I worked on determination of the He^3 /He^4 ratio in cosmic rays using a gas Cerenkov counter and also used a scintillation + solid Cerenkov detector to measure flux of protons and helium nuclei in primary cosmic rays. I also developed a large area scintillation-Cerenkov detector with a spark chamber between them for measuring charge composition of primary cosmic rays. I joined the X-ray astronomy programme in 1967 initiated by Prof. B. V. Sreekantan and played a leading role in developing a balloon borne hard X-ray instrument for studying time variability and energy spectra of cosmic X-ray sources. We carried out a series of balloon experiments and studied temporal intensity variation and energy spectra of X-ray objects like Sco X-1, Cyg X-1, etc. Results on rapid intensity changes and spectra appeared in a series of publications based on which I obtained a Ph.D. degree in 1972. Immediately afterwards, I joined Prof. Gordon Garmire at Caltech as a Research Fellow (a post-doctoral position) to work with him on the low energy component of HEAO A-2 experiment. The instrument was developed and successfully realised. Working on this satellite experiment was a thrilling experience which exposed me to the technical complexities of space instruments. The HEAO-1 satellite was launched in 1978. During 1978–1979, Guenter Riegler and I, working at JPL, reported detection of intense soft X-rays from several classes of extragalactic and Galactic objects like new BL Lacs, a new AM Her binary, coronal X-rays from active stars, etc. After returning to TIFR, I developed a rocket experiment with K. P. Singh to map the spatial and spectral distribution of the Soft Diffuse X-ray Background. At the same time, I also designed 15 cm deep Xenon filled Proportional Counters (XPCs) of ~ 2500 cm^2 area for balloon experiments which were done during 1983–1990 and produced new results on several X-ray binaries. During this period I also developed a proportional counter (PC) based satellite instrument and submitted a proposal jointly with the astronomy group at the Indian Space Research Organization (ISRO) for an Indian X-ray Astronomy Experiment (IXAE). After success of the Polar Satellite Launch Vehicle (PSLV), the IXAE instrument was included on the top deck of the IRS-P3 satellite that was launched in March 1996. Despite the severe limitation of a polar orbit, the IXAE observed a good number of X-ray binaries and produced interesting results, with the most notable being quasi-regular bursts from a new transient, GRS 1915+105, which turned out to be an enigmatic black hole source. Following success of the IXAE, a proposal for an ambitious multiwavelength astronomy satellite, named ASTROSAT, with broad spectral coverage in the optical, NUV, FUV, soft X-ray and hard X-ray by a suite of instruments, was submitted to ISRO and finally approved by the Govt. of India in 2004. Over the next 10 years, the development and fabrication of the five ASTROSAT instruments were accomplished and a PSLV launch on Sept. 28, 2015 placed ASTROSAT in a 650 km circular orbit with 6 degree inclination. The ASTROSAT instruments have been performing well for ~4 years and have observed more than 500 cosmic sources. Results from ASTROSAT have appeared in a large number of journal publications. Successful realization and performance of ASTROSAT marks culmination of my research career. I formally retired as a Senior Professor from TIFR on 2006 April 30 on attaining the age of superannuation. However by agreement with TIFR, ISRO designated me ‘ISRO Chair Professor’, which was later renamed as ISRO Satish Dhawan Professor, and asked me to continue to lead ASTROSAT as PI. At the end of my tenure as ISRO Professor on 2011 April 30, I relinquished the PI position. I am at present affiliated with the MU-DAE Centre of Excellence for Basic Sciences, Mumbai University Campus at Mumbai as an Emeritus Professor.
文摘For the past two years, some real progress has been made in Chinese Space Astronomy, though we have not launched any missions exclusively belonging to the scope of Astronomy. In order to program the next five years' national plan (2006-2010), the Chinese Space Agency organized a series of authorized evaluations for the future missions. Among more than ten astronomical mission proposals, several were selected to give the green light to continue for their Phase A studies. We try to briefly outline these proposals.
文摘In 2008 to 2010,the main activities in Chinese space astronomy were focused on:fulfilling the long-term plan of Chinese space astronomy;initiating the long-term plan of Chinese space astronomy;undertaking some astronomical missions set by CNSA in "Development Program of Space Science for 2006-2010".This paper summarizes in brief all these activities.
文摘In 2006 to 2008,the main activities in Chinese space astronomy focus on:(1) undertaking some missions set by CNSA,like HXMT,SMESE,WSO/UV,SST,KUAFU,and so on;(2) drawing up a long-term plan of Chinese space astronomy.This paper summarizes in brief all these activities.
基金This work was supported by the National Key R&D Program of China(No.2016YFA0400204)the National Natural Science Foundation of China(Nos.11873020,11973097,and U1738210)the Strategic Pioneer Program on Space Science of the Chinese Academy of Sciences(No.XDA15010200)。
文摘Silicon microstrip detectors are widely used in experiments for space astronomy.Before the detector is assembled,extensive characterization of the silicon microstrip sensors is indispensable and challenging.This work electrically evaluates a series of sensor parameters,including the depletion voltage,bias resistance,metal strip resistance,total leakage current,strip leakage current,coupling capacitance,and interstrip capacitance.Two methods are used to accurately measure the strip leakage current,and the test results match each other well.In measuring the coupling capacitance,we extract the correct value based on a SPICE model and two-port network analysis.In addition,the expression of the measured bias resistance is deduced based on the SPICE model.
文摘I returned to China from the United Kingdom in 1953, then worked in Purple Mountain Observatory. It was the early days of new China. The elder generation of astronomers was undertaking an effort of ＂repairing broken and filling defect＂ during those post-war years, and started planning and lay- ing the foundation of modern astronomy. Under their leadership, I started a journey of astronomy whose main task was construction. The journey has been full of twists and turns. As a result of the ＂Great Leap Forward＂ in 1958 and the 1966 launch of the decade-long ＂Cultural Revolution＂ period, the situation of construction in astronomy was similar to that in other sciences, suffering bad effects. Not until the ＂Reform and Opening up＂ period after those events was construction able to continue, and various disciplines and international connections began to open. A ＂passage＂ had gradually developed. In this new circumstance, I kept pursuing the pioneers to explore a forward direction. Looking back today, this journey has been three periods of a four generation relay. This article is divided into three sections that describe my research work in these times that I recall： （1） Looking back at the beginning of the return and tracing the footprints of the founders. （2） Recalling my radio astronomy tour. （3） Retrospection and expectation of LAMOST.
基金supported by the Shanghai Municipal People’s Government
文摘The Educational Adaptive-optics Solar Telescope(EAST)at the Shanghai Astronomy Museum has been running routine astronomical observations since 2021.It is a 65-cm-aperture Gregorian solar telescope for scientific education,outreach,and research.The telescope system is designed in an“open”format so that the solar tower architecture can be integrated with it,and visitors can watch the observations live from inside the tower.Equipped with adaptive optics,a high-resolution imaging system,and an integral field unit spectro-imaging system,this telescope can obtain high-resolution solar images in the TiO and Hαbands,and perform spectral image reconstruction using 400 optical fibers at selected wavelengths.It can be used not only in public education and scientific outreach but also in solar physics research.
文摘Space research is usually costly, and this restricts participation of developing countries. With traditional techniques one must construct high resolution instrument,more and more complicated and expensive, to obtain high resolution results from space observations. It is a difficult task to make observations with both high sensitivity and high resolution. Applying advanced inversion technique, one can subtract more information from old data in public domain,and, furthermore, conduct high sensitive and high-resolution experiments with low-cost low-resolution instruments. So developing and applying data analysis technique is of great importance for developing countries to do basic space science.In this paper we summarize efforts of Chinese scientists in recent years along this direction on imaging in space high energy astronomy.
基金supported by the Polar Research Institute of China and the Chinese Arctic and Antarctic Administrationthe University of New South Wales PLATO teamthe Chinese Academy of Sciences Center for Antarctic Astronomy team
文摘Atmospheric transmission from Dome A, Antarctica, presents new possibilities in the field of terahertz astronomy, where space telescopes have been the only observational tools until now. Using atmospheric transmission measurements from Dome A with a Fourier transform spectrometer, transmission spectra and long-term stabilities have been analyzed at 1.461 THz, 3.393 THz, 5.786 THz and 7.1 THz, which show that important atmospheric windows for terahertz astronomy open for a reasonable length of time in the winter season. With large aperture terahertz telescopes and interferometers at Dome A, high angular resolution terahertz observations are foreseen of atomic fine-structure lines from ionized gas and a water ice feature from protoplanetary disks.
文摘The French astronomer Charles Messier (1730- 1817) compiled a catalogue [1] of astronomical objects which reached109 innumber after additions by later astronomers were added. The catalogue contains galaxies, emission nebulae, a supernova remnant, a double star, globular clusters, open clusters, an asterism, a star cloud, and planetary nebulae. While the objective of Messier in compiling the catalogue was to guide comet hunters not to be confused by his objects which he thought looked like comets [2], the Messier Catalogue as it later became known became a standard guide to astronomers for a study of the sky’s “greatest hits” or the best samples of objects which can be observed and studied. This paper explores the value of the Messier Catalogue in the teaching of Astronomy and Earth Science. The range of objects is wide and contains some of the best examples of their type. The teaching method I propose is the actual observations of the objects through a telescope, with the corresponding explanation. Some principles which will be covered through this process are stellar evolution from the birth and death of stars, galaxy types, formation of galaxies, galactic interactions, life in the Universe, cosmology, and our place in the Universe.
文摘To automate the process of planning and curating multi-target observation sessions, pysky application builds on the astroplan Python package to identify visible objects during an observation window and produce relevant information about those objects in visual and graphical form. The package calculates object visibility based on a provided time window and observing location as well as maximum airmass and limiting magnitude requested by the user. The pysky application images of the target objects with identifying and astrometric data to provide context for the images. In addition, pysky creates polar plots of each object’s horizontal coordinates, and the images and plots are designed to be shown side-by-side. The package also generates an HTML table of the selected target objects with their related data to relay the entire target list as one. The pysky application draws on a variety of Python packages to collect and process data from databases such as JPL Horizons and SIMBAD. Results for a test event were verified by hand using database web interfaces. The pysky application provides a platform for further integration of automated observation planning with websites and apps to enhance multi-target observation sessions.
文摘This chapter reports the recent progress on the space astronomy missions of China,including the following missions:currently operating in orbit,e.g.,DAMPE,Insight-HXMT,GECAM,Polar Light,GRID and Lobster-eye X-ray Satellite;approved and under development for launch in the next a couple of years,e.g.,SVOM and EP;planned experiments to be onboard China’s Space Station in the next several years,e.g.,CSST,HERD,POLAR-2,DIXE and Ly RIC;candidate missions that have passed the first round of review of Strategy Priority Program on space science(Ⅲ)of the Chinese Academy of Sciences,e.g.,eXTP,DAMPE-2,Earth 2.0,DSL and CHES.
